Although I have not yet found acanthus frieze in the Domus Aurea fresco, Volta Dorata, nor in the sculptured ceiling panels of the Criptoportico Neroniano, we do see them here in the Temple of Minerva, in Sbietla, Tunisia. Running along the cavetto, it is plainly visible in the enlargement below

Enlarged decorative detail of the Temple of Minerva,
acanthus frieze lowest (cavetto) under the egg and dart.

Enlarged decorative detail of the Temple of Minerva,
acanthus frieze and scrolls and floral candelabra underneath the Entablature.

No one seems to be able to say exactly when these Classic Roman temples at Sbietla were built. The city of Sbietla was founded just after the reign of Nero "Les témoignages archéologiques du site sont tous postérieurs au ier siècle mais des traces d'une installation humaine antérieure existent dans les environs immédiats.
La ville est fondée par les Romains, sous la dynastie des Flaviens, probablement dans la deuxième moitié du ier siècle" Probably a specialist expert in Acanthus would be able to tell us something more specific about these temples just by the looks of this fantastic candelabra that is seen under the entablature.